Rotary pump.



0. SIEMEN.

ROTARY PUMP.

APPLICATION FILED MAR. 19. 1913.

Patented Apr. 25,1916.

o'rro srnmnn, or NONNENJDAMM, am nEnLrn, snn'nanr, ASSIGNOR 'ro slmltd' scnucxnn'r WERKE, e. M. n. n, or BERLIN, ennnnnx, a oonronarion or enn- MANY.

noranx PUlltUE.

Specification of Letters Patent.

Application filed March 19, 1913. Serial No. 755,439.

To all whom it mag concern:

Be it known that I, O'r'ro SIEMEN, a citizen of the German Empire, and residing at Nonnendamm, near Berlin, Germany, have invented certain new and useful Improvements in Rotary Pumps, of which the fol.-'

lowing is a specification.

My invention relates to rotary pumps of the known type in which the blade-Wheel is journaled eccentrically in .the pump-casing, the various spaces or cells formed by each two blades being packed at the side nearest the casing by a ring of liquid formed in the casing by centrifugal actiondue to the rapid rotation of the blade-wheel. These pumps are particularly suitable for conveying gases, such as air or for taking in steam' mixture of steam and air, and is actually employed in practice for condensing plants for the purpose of drawing off the condensing steam of reciprocating steam engines and steam turbines. The mixture of steam and air is carried from the condenser into the pump, and immediately after entering the pump the steam-of said mixture will be condensed by action of the liquid ring and in this manner only air be carried by the pump. Pumps with liquid ring as compared with dry plunger pumps have the advantage of being of smaller size for the same'quantity of the condensed water. The reason for this is found therein that in pumps with liquid ring the steam is immediately condensed so that only air will be carried in the pump, while a dry pump wlll not cause the condensing of the steam after its entrance and consequently a mixture of steam and air will be carried through the ump.

By the term ratio of suction and delivery pressures there will be understood the ratio between the pressure existing at the suction side and the pressure existing at the pressure side. In case the pumps have normal inlet and exhaust openings this pressure ratio of the pump is constant, assuming a constant per pheral velocity of the pump wheel, while n the pump according to my present invention this pressure ratio .will be variable for the same peripheral velocity.

A primary object of my invention is to make a pump of the described type adapt itself automatically to a variable ratio of suction and delivery pressures. To effect this, both the magnitude of the outlet openng and relative position of the outlet and inlet openings of the pump must vary automatically according to the desired ratio.

Accordin to my invention I attain this end by ma mg the outlet opening not as one continuous opening, but subdivided into several separate openings or ports arranged one behind another in the direction of flow oi? the medium to be conveyed; these individual openings or ports are closed .and opened in the discharge chamberof the pump by a liquid or by solid bodies which acts or act like valves.

Several illustrative embodiments of my invention are represented by way of example in the accompanying drawing, wherein Figure 1 -is a vertical section through the pump taken at right angles to its shaft,-and Fig. 2 is a like view taken on the line A-B in Fig. 1. Fig. 3 is an elevation showing the suction and discharge chambers .of the Patented a as, mic.

pump after one of the covers has been removed; is shows the plate having the inlet and outlet openings as seen from the side opposite to that shown in Fig. 1. Figs. 4

.to 10 are detail views showing modified forms of the outlet openings of the pump. described hereinafter.

Referring firstly to Figs. 1 to 3, a: designates the casing of the pump in which the eccentrically journaled blade-wheel b rotates in the direction indicated by the.ar-

, row shown in Fig. 1. The blades h of this other side by the cover 9.

The water requisite for forming the rotating ring of liquid is constantly replenished. The excess water flows away into the discharge chamber m and completely fills this because the delivery pipe at is connected to the top thereof. The subdivided outlet opening in the plate [9 is consequently I closed 'gas tight by water in the discharge chamber.

Assuming the pump to operate as a gas or air compressing pump its action is as follows:W'hen the ratio of the suction and delivery pressures is great the gas or air sucked in is not discharged at those ports (I, which are located farthest from the crown a, because it has not yet at this place been compressed to a pressure exceeding the high pressure existing in the discharge chamber m. On .the contrary liquid will flow back out of the discharge chamber m through these lowest ports (2, into the casinga. The

quantity of such liquid which flows back -is, however, relatively very small because the velocity at which water moves 1s materially less than that of. air at the same pressure. Thus the water. inthe subdivided outlet opening in the plate 7? constitutes a closure member whose action perfectly corresponds to that of a non-return or check valve.

In case of a prescribed speed of rotation of the pump according to my invention a definite compression path for the suction opening 0 to the pressure opening d will be required in order to attain a definite pressure ratio. If this pressure ratio'is small, the quantity of the gas drawn off is only little decreased and this gas will be carried through all discharge openings (1} into the exhaust space m, thus rendering the path of compression small. If however a high pressure ratio between suction and pressure side shall be attained, the quantity of the gas drawn ofi must be considerably decreased and for the same speed of rotation of the pump a longer path of compression will be necessary.

By the arrangement according to my present invention the magnitude of the discharge openings will be automatically decreased in case of a great pressure ratio and thereby the path of compression will be prolonged by' keeping closed the discharge openings (Z which are at a greatest distance from the vertex a, of the pump.

In Figs. 3 to 10 various forms or arrangements of the subdivided outlet opening are represented. Fig. 3 shows simple round orifices or ports d, located one behind another in rows in the direction of flow of the medium being conveyed. The portion d of the opening located nearest the crown a need not be subdivided, but may be continuous, as shown in Figs. 1, 3', 4, 5 and 7. Instead of round orifices oval slots (I, may be provided, as shown in Fig. 4.

The above described valve-like action can be increased by forming the orifices as passages, because the increased friction offers increased resistance to the water. Such an arrangement is shown-in Fig. 5, in which downwardly directed tubes d, are shown ing connected withtubes which open low .down in the chamber, while the upper orifices are connected to tubes which open higher up. Also, it may be preferable to separate the orifices located beside one another in a row by means of walls or partitions, as shown in Fig. 7. Such partitions may also be employed between the outlets of passages arranged in the plate (Z itself. When tubes are employed the purpose in view is obtained when, as shown in Fig. 8, the lower ends of the downwardly directed tubes are bent upward.

Instead of obtaining the valve action by means of orifices or ports closed by water in the discharge chamber, this valve action may, of course, be obtained by means of mechanical valves t which, as shown in Fig. 9, are formed as ball-valves. If desired, flap valves may be employed.

In Fig. 1 the inlet opening 0 is shown as one connected opening. If desired. there is, of course, no objection to subdividing this opening also into various smaller orifices and providing them with valves. The mediluu being conveyed will then be prevented from flowing back into the suction chamber when it is sufficiently compressed at those parts of the suction opening which are located farthest from the crown (1,.

In order as much as possible to diminish loss of pressure when the medium being conveyed flows out of the interior of the pump without. however, facilitating the return of the liquid, the openings or ports in the plate ;0 may be made wider at the inner side of the plate than at the side bounding the distil-i may be connected in series in a common or 1n separate casings.

I claim 1. In arotary pump of the character described, the combination of a casing having an inlet opening and an outlet opening, a blade-Wheel mounted eccentrically in the casing and adapted, when rapidly rotated, to cause liquid suppliedinto the casing to assume the form of a rotating ring in the casing, and a discharge chamber having a delivery outlet in the upper part thereof and being connected by way of said outlet opening with the interior of the casing; said outlet opening being subdivided into a plurality of separate orifices located one behind another in the direction of rotation of the ring of liquid, and the discharge chamber being normally filled with liquid for closing and opening the said orifices in the manner of a valve,

2. In a rotary pump of the character described, the combination of a casing having an inlet opening and an outlet opening, a blade-wheel mounted eccentrically in the casing and adapted, when rapidly rotated, to cause liquid supplied into the casing to assume the form of a rotating ring in the casing, and a discharge chamber having a delivery outlet in the upper part thereof and being connected by way of said outlet opening with the interior of the casing; said out let opening being subdivided into a plurality of separate passages located one behind another in the direction of rotation of the ring of liquid, and the discharge chamber.

being normally filled with liquid for closing and opening the said passages in the manner of a valve.

3. In a rotary pump of the character described, the combination of a casing having an inlet opening and an outlet opening, a blade-wheel mounted eccentrically in the casing and adapted, when rapidly rotated, to cause liquid supplied into the casing to assume the form of a rotating ring in the casing, and a discharge chamber having a delivery outlet in the upper part thereof and being connected by way of said outlet opening with the interior of the casing; said outlet opening being subdivided into a plurality of separate orifices located one behind another in the direction of rotation of the ring of liquid, tubes in the discharge chamber each having one end connected to one of said orifices, and the discharge chamber being normally filled with liquid for closing and opening the other ends of said tubes in the manner of a valve.

l. In a rotary pump of the character described, the combination of a casing having an inlet opening and an outlet opening, a blade-wheel mounted eccentrically in the casing and adapted, when rapidly rotated, to cause liquid supplied into the casing to assume the form of a rotating ring in the casing, and a dischargechamber having a delivery outlet in the upper part thereof and being connected by way of said outlet opening with the interior of the casing; said outlet opening being subdivided into a plurality of separate passages located one behind another in the direction of rotation of the ring of liquid, and the discharge chamber being normally filled with liquid for closing and opening the said passages in the manner of a valve, the passages connected to orifices located farther from the crown of the casing opening into the discharge chamber lower down than the passages connected to orifices located nearer the crown.

5. In a rotary pump of the character described, the combination of a casing, a plate having an inlet opening and a subdivided outlet opening dividing the easing into two chambers, a blade-wheel. mounted eccentrically in one of said chambers and adapted,

when rapidly rotated, to cause liquid supplied into the chamber to take up the form of a rotating ring in the chamber, a wall dividing the other of said chambers into a sup-ply chamber connected with said inlet opening and into a discharge chamber connected with said outlet opening, the supply chamber having a supply inlet, and the discharge chamber having a delivery outlet in the upper part thereof, the subdivisions or ports of the outlet opening being located in one or more rows in the direction of rotation of the blade-Wheel, and the discharge chamber being normally filled with liquid for closing and opening the subdivisions of the outlet opening in the manner of a valve.

6. In a rotary pump of the character described, the combination of a casing having an inlet opening and an outlet opening, a blade-Wheel mounted eccentrically in the casing and adapted, when rapidly rotated, to cause liquid supplied into the casing-to assume the form of a rotating ring in the casing, and a discharge chamber having a delivery outlet in the upper part thereof and being connected by way of said outlet opening with the interior of the casing; said outlet opening being subdivided into a plurality of separate orifices located one behind another in the direction of rotation of the ring of liquid and the discharge chamiia' Mitt

ber being normally filled with liquid for closing and opening the said orifices in the manner of a valve; discharge chamber located between the ori 5 fices.

scribed, the combination of a casing having an inlet opening and an outlet opening, a blade-wheel mounted eccentrically in the 10 casing and adapted, when rapidly rotated,

to cause liquid sup-plied into the casing to assume the form of a rotating ring in the casing, anda discharge chamber having a delivery outlet in the upper part thereof 15 and being connected by way of said outlet and partitions in the.

7. In a rotary pump of the character de-- opening with the interior of the casing; said outlet opening being subdivided into a 1plurality of separate ori ces located one beind another in the direction of rotation of the ring of liquid, and valves opening away 20 fromthe blade-wheel in the orifices located farther away from the crown of the casing. Intestimony whereof I have signed my name to this specification in -the presence of two witnesses.

OTTO SIEMEN.

Witnesses:

HENRY HAsPER, WOLDEMAR HAUPT. 

